Prefab houses, which are manufactured in a factory like a giant wind turbine or SUV and conveyed to their sites, appear to represent a step forward in housebuilding.
Supporters of prefabricated housing point out that the homes are higher quality. The hammer and nail route can be a difficult one, with mistakes being almost inevitable when windows, doors, plumbing, and other components are put on site in a short timeframe. There is less disruption in the neighbourhood when homes are built in four days and dropped on site instead of constructed over a period of months. Productivity is also improved because there are no delays due to bad weather, materials shortages, or worker error.
Times look set to change. In Japan, over 15% of new homes are prefabricated by companies such as Daiwa House, Misawa Homes and Sekisui House, which specialise in producing factory-perfect homes. The output is an estimated 10,000 durable, high-quality, and long-lasting homes a year.
Less than 10% of the new-build market in the UK is self-build, but several companies are starting to produce interesting prefab homes. NHouse makes a model that looks upscale compared to regular new-builds. The three-bedroom homes are approximately 20 square metres larger than the comparable average. They are constructed from cross-laminated hardwood and materials guaranteed to last 50 years. The windows are large, the ceilings high, and the buildings contain wide range of energy-efficient features. These homes generate an estimated 75% less traffic in the construction process than prefab houses and can be set up at any designated location in three days.